I've spotted this name recently in some things I've been transcribing for FreeREG. They updated the database yesterday, and having just done a quick search, it must've been Great Holland I'm thinking of (which might be too far out, and doesn't include a Jonah).
Saying that, it does bring up a baptism for a Jonah Beckwith in Bocking on 28 Aug 1684, son of Samuel - might that be a connection?
Have you looked at the non-conformist registers?
The surname stuck in my mind because I was at school with a girl called Beckwith who I think lived somewhere near Braintree!